<?php

class Atom {
	
	function __construct() {
		
	}
	
	/**
	 * Creates the XML Atom feed of a list of items, to be used for a feed or collection
	 * 
	 * @param array
	 * @return string
	 */
	public function createFeed($items) {
		$feed = '';
		
		foreach ($items as $item) {
			$feed .= $this->createEntry($item);
		}
		
		return $feed;
	}
	
	/**
	 * Creates an XML Atom entry from an item
	 * 
	 * @param array
	 * @return string
	 */
	public function createEntry($item) {
		
	}
	
	/**
	 * Create a UUID for items stored in the database
	 *
	 * @param string $prefix Prefix might be 'urn:uuid:'
	 * @return string
	 */
	public static function uuid($prefix = '') {
		$chars = md5(uniqid(rand()));
		return $prefix . substr($chars,0,8) . '-' .
				substr($chars,8,4) . '-' .
				substr($chars,12,4) . '-' .
				substr($chars,16,4) . '-' .
				substr($chars,20,12);
	}
	
}

/*
   <feed xmlns="http://www.w3.org/2005/Atom">
     <title type="text">dive into mark</title>
     <subtitle type="html">
       A &lt;em&gt;lot&lt;/em&gt; of effort
       went into making this effortless
     </subtitle>
     <updated>2005-07-31T12:29:29Z</updated>
     <id>tag:example.org,2003:3</id>
     <link rel="alternate" type="text/html"
      hreflang="en" href="http://example.org/"/>
     <link rel="self" type="application/atom+xml"
      href="http://example.org/feed.atom"/>
     <rights>Copyright (c) 2003, Mark Pilgrim</rights>
     <generator uri="http://www.example.com/" version="1.0">
       Example Toolkit
     </generator>
     <entry>
       <title>Atom draft-07 snapshot</title>
       <link rel="alternate" type="text/html"
        href="http://example.org/2005/04/02/atom"/>
       <link rel="enclosure" type="audio/mpeg" length="1337"
        href="http://example.org/audio/ph34r_my_podcast.mp3"/>
       <id>tag:example.org,2003:3.2397</id>
       <updated>2005-07-31T12:29:29Z</updated>
       <published>2003-12-13T08:29:29-04:00</published>
       <author>
         <name>Mark Pilgrim</name>
         <uri>http://example.org/</uri>
         <email>f8dy@example.com</email>
       </author>
       <contributor>
         <name>Sam Ruby</name>
       </contributor>
       <contributor>
         <name>Joe Gregorio</name>
       </contributor>
       <content type="xhtml" xml:lang="en"
        xml:base="http://diveintomark.org/">
         <div xmlns="http://www.w3.org/1999/xhtml">
           <p><i>[Update: The Atom draft is finished.]</i></p>
         </div>
       </content>
     </entry>
   </feed>
*/